Packaging for a product comprising at least one hygroscopic flowable solid

ABSTRACT

In packaging ( 1 ) for a product ( 3 ) comprising at least one hygroscopic flowable solid, a drying wrapping ( 10 ) made from a moisture-impermeable material which surrounds a product bag ( 2 ) filled with the product ( 3 ) is arranged in a transport container ( 4 ), and in which the desiccant ( 14 ) is arranged on an inside ( 11 ) of the drying wrapping ( 10 ) facing the product bag ( 2 ). The desiccant ( 14 ) is arranged in at least one, preferably in a plurality of desiccant bags ( 13 ). The at least one desiccant bag ( 13 ) is covered and fixed by a moisture-permeable perforated covering ( 16 ) on the inside ( 11 ) of the drying wrapping ( 10 ).

The invention relates to packaging for a product comprising at least onehygroscopic flowable solid, where the packaging has a sealable productbag made from a moisture-permeable material for the accommodation of theproduct, a transport container surrounding the product bag, and adesiccant which is arranged outside the product bag and inside thetransport container.

In the chemical or pharmaceutical industry, hygroscopic flowable solids,such as, for example, pulverulent substances, often have to betransported and stored before they are supplied for a use as intended.Numerous different types of packaging for this purpose are known frompractice. In the case of many different types of packaging, the productor the chemical substance is introduced into a sealable product bag forprotection against contamination and subsequently introduced into atransport container. The transport container can be, for example, a drumor a crate.

In the case of a product which either consists of a hygroscopicsubstance or comprises at least one hygroscopic component and is inpulverulent or granular or flowable form, the danger regularly existsthat, due to moisture during the filling operation or subsequentlyduring transport or storage, the product clumps due to residualmoisture. If an excessive amount of moisture reaches and enters theproduct over an extended period, the flowability of the product may bereduced or disappear completely and the product may cake, forming one ormore large lumps.

In order to reduce the risk of clumping or caking of the product duringtransport and storage, it is known to design the surrounding transportcontainer to be moisture-tight and to seal it in a moisture-tight mannerafter filling with the product. However, it is nevertheless not possibleto exclude the possibility of moisture entering the interior of thetransport container during filling and in particular during successiveremoval of the product and consequent repeated opening and sealing ofthe transport container and resulting in clumping or caking of thehygroscopic product.

In order to avoid these disadvantageous effects of moisture present inthe transport container, it is known from practice to arrange adesiccant in the transport container, which absorbs and stores moisturepresent in the transport container. The desiccant is usually arranged ina bag or in a plurality of bags. These desiccant-filled desiccant bagsare placed in the transport container either before or after theproduct-filled product bag. WO 2003/004380 A2 describes packaging inwhich a plurality of bags filled with a desiccant are arranged in aninterspace between the product bag and the transport container. However,it is not possible to exclude the possibility, in particular duringmovement and shaking of the transport container, for example due totransport, of the desiccant bags leaving their initial position andaccumulating somewhere within the transport container, causing furtherabsorption of moisture to be concentrated in the region around thedesiccant bags and making absorption of moisture by the desiccant bagsin regions remote therefrom more difficult.

It is known from practice that the desiccant bags are fixed in theregion of a sealable opening of the product-filled product bag, forexample by means of bands or loops. The effort necessary for thispurpose is considerable. Although the desiccant bags can be arranged andfixed in the region of the opening of the product-filled product bag,they cannot be arranged and fixed at any desired place in the productbag or within the transport container without major effort.

It is likewise known from practice to arrange a moisture-permeableaccommodation device in the transport container, in which a desiccantbag can be arranged. Transport containers which have accommodationdevices of this type, for example in the form of small pockets or meshboxes, for the accommodation of a desiccant bag are described, forexample, in U.S. Pat. No. 6,102,198 and are complex and expensive toproduce. The accommodation devices project into the interior of thetransport containers and may under certain circumstances damage theproduct-filled product bag. The transport container provided with theseaccommodation devices must either have been intended for this purposeand produced correspondingly, or alternatively retrofitted with theaccommodation devices. Besides the costs additionally arising for thispurpose, it is frequently regarded as a severe disadvantage that onlycorresponding transport containers are suitable for the transport ofhygroscopic products and these have to be kept ready in sufficientamount and separately from transport containers without accommodationdevices of this type.

It is therefore regarded as an object of the present invention to designpackaging for a product comprising at least one hygroscopic flowablesolid component in such a way that moisture can be absorbed in thetransport container inexpensively using the simplest possible means andclumping or caking of the hygroscopic product can be reduced orprevented entirely.

This object is achieved in accordance with the invention in that adrying wrapping which can be detached from the transport container andis made from a moisture-impermeable material which surrounds the productbag containing the product is arranged in the transport container, andin that the desiccant is arranged on an inside of the drying wrappingfacing the product bag containing the product. Due to the use of adrying wrapping, the arrangement of the desiccant inside the transportcontainer or in the vicinity of the product bag containing the productcan be pre-specified independently of the product bag used for theaccommodation of the product and independently of the transportcontainer. Expensive and complex modifications of the transportcontainer are not necessary. It is equally unnecessary to attach thedesiccant to the product bag or in the closure region of the product bagafter the product bag has been filled with the product and the productbag has subsequently been sealed.

The use of a drying wrapping which can subsequently be placed in atransport container which is already present enables the transportcontainers which are already present to be retrofitted and used for thetransport of hygroscopic products. Since the drying wrapping can be usedwith various transport containers, existing distribution systems withthe corresponding transport containers can be retained unchanged. Theadditional cost for the acquisition and use of the drying wrapping isextremely low.

The drying wrapping can be designed to be re-usable and can remain inthe transport container after the product bag containing the product isremoved, so that the drying wrapping continues to be available forre-use of the transport container. It is likewise possible to produceand intend the drying wrapping for a single use and to design it as adisposable product.

The use of a product bag which consists of a moisture-permeable materialenhances the action of the desiccant. Should residues of moisture bepresent in the product bag or in the product located therein oraccumulate after opening and re-sealing of the product bag, thismoisture is transported through the moisture-permeable product bag intothe interspace between the product bag and the surrounding dryingwrapping, where it can be absorbed and bound by the desiccant.

According to an embodiment of the inventive idea, it is provided thatthe desiccant is arranged in at least one desiccant bag which is fixedto an inside of the drying wrapping. Desiccant bags of this type arecommercially and inexpensively available in numerous variants and shapesfor different desiccants. The desiccant bag can be fixed to the dryingwrapping simply and reliably, for example by welding, adhesive bondingor sewing. A plurality of desiccant bags are advantageously fixed to thedrying wrapping at a separation from one another in order to favour theabsorption of moisture by the desiccant located in the desiccant bagsand in order to prevent the desiccant from concentrating in a smallregion within the transport container and the moisture not beingabsorbed or only being absorbed to a small extent in other regions.

Particularly simple and effective fixing of the desiccant bags to thedrying wrapping can be achieved in that the at least one desiccant bagis covered and fixed by a moisture-permeable covering on the inside ofthe drying wrapping. The moisture-permeable covering may be perforatedand made from the same moisture-impermeable material as the dryingwrapping. If the drying wrapping consists, for example, of a film, thedesiccant bags can be arranged in pockets produced by multipleturning-over and subsequent fixing, or adhesive bonding or welding ofthe pockets of the drying wrapping formed in this way.

According to a particularly advantageous embodiment of the inventiveidea, it is provided that the drying wrapping is matched to the shape ofthe transport container. The drying wrapping can be placed in theinterior of the transport container and can form an inner lining of thetransport container. Due to the matching of the drying wrapping to theshape of the transport container, the arrangement of the drying wrappingin the transport container or relative to the transport container can bepre-specified and the position of the desiccant bags fixed to the dryingwrapping in the interior or on the walls of the transport container canthus be pre-determined. Due to the drying wrapping lying against thetransport container, the filling of the transport container with theproduct bag which is itself filled with the product does not become moredifficult.

It is likewise conceivable and advantageous for individual applicationsfor the drying wrapping to be matched to the shape of the product bag.The product-filled product bag can then be introduced into the dryingwrapping, with the arrangement of the desiccant or the individualdesiccant bags relative to the filled product bag being pre-specified.In this way, a highly uniform distribution of the desiccant on theproduct bag and thus in the immediate vicinity of the product can alsobe ensured for the case where the filled product bag only occupies apart-region of the transport container and its position and shape withinthe transport container frequently change during transport.

For many applications or products, it is already sufficient for a fewdesiccant bags to be arranged in the transport container. In thesecases, it may be advantageous for the desiccant only to be arranged in aregion of the drying wrapping facing an opening of the transportcontainer. During filling of the transport container, an unused volumeusually remains in the region of the opening of the transport container.After sealing of the transport container, air, which generally has amoisture content, is located in this volume. The arrangement of thedesiccant in this region facilitates effective dehumidification of theair present in the transport container. In addition, fresh and moist airflows into the transport container each time the transport container isopened, for example for successive and gradual removal of the product.This air accumulates in the region close to the opening, where it can beeffectively dehumidified.

In particular in the case where high air humidity is expected or in thecase of a particularly moisture-endangered product, it may beadvantageous to arrange the desiccant distributed over the entire insideof the drying wrapping. In this way, for example, a relatively largenumber of desiccant bags can be fixed to the drying wrapping distributedat regular or alternatively irregular separations over the inside of thedrying wrapping. Irrespective of the shape of the product-filled productbag and independently of the amount of product remaining in thetransport container after partial removal, it can thus be ensured that aplurality of desiccant bags are arranged at a separation from oneanother in the vicinity of the product bag.

In order to support dehumidification of the product located in theproduct bag, it is provided that the product bag is a textile nonwovenmade from thermally welded high density polyethylene (HDPE) fibres. Anonwoven material of this type is already extensively employed inpractice. Besides high permeability to moisture and air, theadvantageous properties of a nonwoven material of this type also includehigh tear strength and straightforward use together with numeroushygroscopic products from the chemical industry or pharmaceuticalindustry.

A particularly inexpensive and at the same time effective andmoisture-impermeable drying wrapping consists of a thin polyethylenewrapping or film, or comprises a thin polyethylene wrapping of this typeas coating or individual layer of the drying wrapping. With a view tosimple and inexpensive production, the individual desiccant bags arecovered and fixed by a covering on the inside of the drying wrapping,where this covering may likewise consist of a thin polyethylene film,which is moisture-permeable owing to a perforation.

BRIEF DESCRIPTION OF FIGURES

The invention is explained in greater detail with reference to aplurality of illustrative embodiments, which are depicted in thedrawing, in which:

FIG. 1 shows a sectional view of packaging with a transport container,with a drying wrapping arranged in the transport container, and with aproduct-filled product bag,

FIG. 2 shows a sectional view of another packaging in which the dryingwrapping surrounds and lies closely against the product-filled productbag, and

FIG. 3 shows a sectional view of yet another embodiment of packaging, inwhich the drying wrapping lying against the transport container has aplurality of desiccant bags which are fixed laterally to the dryingwrapping by a perforated covering.

Packaging 1, depicted by way of example in FIG. 1, has a sealableproduct bag 2, which is filled with a flowable hygroscopic product 3.The product bag 2 consists of a moisture-permeable nonwoven materialmade from high density polyethylene (HDPE) fibres. The hygroscopicproduct 3 can be, for example, a chemical substance which is requiredfor the production of end products in the chemical or pharmaceuticalindustry.

The sealable product bag 2 is arranged in a transport container 4surrounding the product bag 2. The transport container 4 has a drum-likebasic body 5, which can be sealed by means of a lid. The transportcontainer 4 consists of a moisture-impermeable material, for examplepolyethylene. The lid 6 can be arranged and fixed on the basic body 5 ina moisture-tight manner by additional sealing elements 7 in order toseal the transport container 4 in a moisture-tight manner. If it appearsnecessary, the sealed transport container 4 can additionally be providedwith a tamper-proof seal, for example in the form of a lead seal 8.

A drying wrapping 10 matched to the shape of the transport container 4is arranged in an interior 9 of the transport container 4. The dryingwrapping 10 consists of a thin polyethylene film and is likewisedesigned to be moisture-impermeable. A plurality of desiccant bags 13are adhesively bonded to the inside 11 of the drying wrapping 10 in aregion 12 of the drying wrapping 10 facing the lid 6 of the transportcontainer 4 on an inside 11 of the drying wrapping 10 facing the productbag 2 with the product 3 located therein. The desiccant bags 13 containa suitable desiccant 14, for example silica gel or zeolites, anhydroussodium sulfate or magnesium sulfate.

Moisture present in the free interior 9 of the transport container 4 isabsorbed and bound by the desiccant 14 in the desiccant bags 13, whichare arranged in this region 12 of the drying wrapping 10. If residues ofmoisture are present in the product 3, these are transported through theproduct bag 2 into the interior 9 of the transport container 4, which isthen dry, where they are likewise absorbed and bound by the desiccant14.

In the case of the illustrative embodiment depicted in FIG. 2, the shapeof the drying wrapping 10 is matched to the shape of the product bag 2,so that the drying wrapping 10 surrounds and lies closely against thefilled product bag 2. A plurality of desiccant bags 13, each of whichcontain a portion of the desiccant 14, are attached to the inside 11 ofthe drying wrapping 10 at regular separations. The product bag 2 and theproduct 3 located therein are accordingly evenly dehumidified from allsides. The shape of the surrounding transport container 4 is unimportantin this variant of the packaging 1.

In the case of the illustrative embodiment depicted in FIG. 3, the shapeof the drying wrapping 10 is matched to the shape of the transportcontainer 4, so that the drying wrapping 10 forms a lining of the sidewalls and base of the transport container. The drying wrapping 10 can beplaced in the transport container 4 before the introduction of theproduct bag 2 and does not hinder the subsequent introduction of theproduct bag 2, even in a state already filled with the product. Thedrying wrapping 10 has desiccant bags 13, each containing a portion ofthe desiccant 14, distributed over its side surfaces 15. Each individualdesiccant bag 13 is covered by a covering 16 comprising a section of apolyethylene film matched thereto, and is fixed to the side surface 15of the drying wrapping 10. The individual coverings 16 are each providedwith a perforation 17, so that the coverings are moisture-permeable inspite of the moisture-impermeable material polyethylene.

The present description will enable the person skilled in the art toapply the invention comprehensively. Even without further comments, itis therefore assumed that a person skilled in the art will be able toutilise the above description in the broadest scope.

For better understanding and in order to illustrate the invention,examples which fall within the scope of protection of the presentinvention are given in the drawings FIG. 1, FIG. 2 and FIG. 3. Inaddition, the embodiments depicted may exist in modified variants. Owingto the general validity of the inventive principle described, theexamples shown in the drawings are therefore not suitable for reducingthe scope of protection of the present invention to these alone.

1. Packaging (1) for a product (3) comprising at least one hygroscopicflowable solid, where the packaging (1) has a sealable product bag (2)made from a moisture-permeable material for the accommodation of theproduct (3), a transport container (4) surrounding the product bag (2),and a desiccant (14) which is arranged outside the product bag (2) andinside the transport container (4), characterised in that a dryingwrapping (10) which can be detached from the transport container (4) andis made from a moisture-impermeable material which surrounds the productbag (2) containing the product (3) is arranged in the transportcontainer (4), and in that the desiccant (14) is arranged on an inside(11) of the drying wrapping (10) facing the product bag (2). 2.Packaging (1) according to claim 1, characterised in that the desiccant(14) is arranged in at least one desiccant bag (13) which is fixed tothe inside (11) of the drying wrapping (10).
 3. Packaging (1) accordingto claim 2, characterised in that the at least one desiccant bag (13) iscovered and fixed by a moisture-permeable covering (17) on the inside(11) of the drying wrapping (10).
 4. Packaging (1) according to claim 3,characterised in that the moisture-permeable covering (17) isperforated.
 5. Packaging (1) according to claim 1, characterised in thatthe drying wrapping (10) is matched to the shape of the product bag (2).6. Packaging (1) according to claim 1, characterised in that the dryingwrapping (10) is matched to the shape of the transport container (4). 7.Packaging (1) according to claim 1, characterised in that the desiccant(14) is only arranged in a region (12) of the drying wrapping (10)facing an opening of the transport container (4).
 8. Packaging (1)according to claim 1, characterised in that the desiccant (14) isarranged distributed over the inside (11) of the drying wrapping (10).9. Packaging (1) according to claim 1, characterised in that the productbag (2) for the accommodation of the product (3) is a textile nonwovenmade from thermally welded high density polyethylene (HDPE) fibres. 10.Packaging (1) according to claim 1, characterised in that the dryingwrapping (10) is or comprises a thin polyethylene wrapping.